There are processes in the art teaching the production of carboxylic acids and esters from olefins using a variety of catalyst systems. However, in these processes the catalyst is usually complex and the use of a carbon bed is not suggested.
U.S. Pat. No. 4,303,589 discloses a process for hydroesterification of internal olefins to produce carboxylic esters of high normality over a cobalt catalyst at 170.degree.-200.degree. C. and 1200 to 1800 psi. High concentrations of cobalt are required.
U.S. Pat. No. 2,739,169 discloses a method for the preparation of propionic acid which comprises reacting diethyl ether, water and carbon monoxide in the presence of a three component catalyst generated from a three component mixture comprising nickel chloride, hexahydrate, copper and sodium iodide. This process does not address production of iso and n-butyric acids and esters.
In Journal of Molecular Catalysts, 10 (1981) 161-170, Caminato and Toniolo discuss the hydrocarboalkoxylation of propene promoted by a palladium platinum complex catalyst precursor at 100.degree. C. to 110.degree. C. with high selectivity toward the branched isomer when a solvent is added to the alkanol.
The reaction of olefins with carbon monoxide and water in the presence of a variety of transition metal catalysts is disclosed in "Mechanistic Pathways in the Catalysis of Olefin Hydrocarboxylation by Rhodium, Iridium, and Cobalt Complexes", CATAL. REV. SCI. ENG., 23 (1 and 2), 89-100 (1981).
In U.S. Pat. No. 3,917,677 carboxylic acid esters are prepared by reacting ethylenically unsaturated compounds with carbon monoxide and alcohols in the presence of a catalyst solution essentially comprising a rhodium component and a tertiary organophosphorous component, said solution being essentially free of halogen.
An article by Fenton entitled "Noble Metal Catalysis II Hydratocarbonylation Reaction of Olefins with Carbon Monoxide to Give Saturated Acids" in J. Org. Chem., Vol. 38, No. 18, 3192 (1973) discloses a process for hydratocarbonylation of olefins with carbon monoxide to give saturated acids wherein the catalyst employed is a zero valent palladium phosphine complex.
For a general discussion of carbonylation of olefins see I. Wender and P. Pino, Organic Synthesis via Metal Carbonyls, Vol. 2, p. 233-296, John Wiley and Sons, N.Y., 1977.
It would be a considerable advance in the art to provide a catalyst system for preparation of carboxylic acids from olefins, methanol and carbon monoxide which uses much lower concentrations of soluble metal catalysts than used in prior art, which allows for ease of separation of catalyst and product and which produces a mixture of valuable chemicals such as n-butyric acid, isobutyric acid, acetic acid and methyl acetate. The isobutyric acid and esters are useful in preparation of methacrylic acid and esters. n-Butyric and isobutyric acid are useful for preparation of synthetic lubricants. Acetic acid has a myriad of industrial uses including the preparation of vinyl acetate, a useful monomer used for creating valuable polymers.